1. Getting the speed gains is hard unless you are able to pay for dedicated GPUs. Some services offer LoRA as serverless but you don't get the same performance for various technical reasons.
2. Lack of talent to actually do the finetuning. Regular engineers can do a lot of LLM implementation, but when it comes to actually performing training it is a scarcer skillset. Most small to medium orgs don't have people who can do it well.
3. Distribution. Sharing finetunes is hard. HuggingFace exists, but discoverability is an issue. It is flooded with random models with no documentation and it isn't easy to find a good oen for your task. Plus, with a good finetune you also need the prompt and possibly parsing code to make it work the way it is intended and the bundling hasn't been worked out well.